1. Field of the Invention
The present invention relates to a retainer member for inhibiting or preventing relative rotation between a plurality of fastener elements which are arranged in predetermined spaced relationship with each other, and more particularly, relates to an apertured retainer plate for preventing the rotation of nuts which are screw-fitted onto the threaded shanks of bolts so as to facilitate the tightening and torquing of the bolts on the nuts, or alternatively, facilitate the loosening and disengagement between previously fastened together bolts and nuts.
Moreover, the invention is also directed to the provision of a plurality of the plate-shaped retainer members being arrangeable in a contiguous relationship with each other and thereby collectively defining a specified bolt circle having the apertures therein located at annular positions in conformance with bolt holes formed in structures, such as mating flanges. This enables positioning in the apertures of the retainer plates a plurality of nuts which are sized in general conformance with the shapes of the apertures, which nuts are screw-fittingly engageable by the threaded shanks of bolts for implementing the locking engagement between the mating flanges, and as a consequence of which there is enabled the tightening and torquing of the bolts on the therewith engaged nuts with minimum exerted effort and at considerable savings in expenditures of labor and time; while, conversely, there is also facilitated the loosening and disengagement between the respective fastened together bolts and nuts.
In numerous physical plants and installations; for example, such as chemical reactor systems, petrochemical manufacturing facilities or the like, among diverse other installations and processing plants requiring extensive pipe lines and attendant mating flange connections, the assembly and fastening together of such flanges through the intermediary of nuts and therewith associated screw-fitted threaded bolts becomes quite time consuming and labor intensive, inasmuch as special efforts must be expended in order to prevent the rotation of the nuts while tightening and torquing the therewith screw-fitted bolts. In essence, this normally entails the appropriate personnel; for instance, a pipefitter effecting manual gripping of each of the nuts, such as through the use of suitable wrenches or the like, and then implementing rotation of the respective bolts engaging the nuts, and torquing the bolts with suitable torquing wrenches while holding the nuts so as to be secure from rotation, to thereby provide for the necessary tightening and torquing action; or conversely, disengaging any previously fastened together bolts and nuts. This cumbersome, two-handed manual procedure frequently renders it difficult for the pipefitter to carry out the appropriate torquing, and also necessitates that each and every individual nut positioned along the bolt circle of the mating flanges must be manually held in position to inhibit respective rotation thereof during the tightening and torquing or loosening of the therewith associated bolt.
2. Discussion of the Prior Art
Although various devices are currently known in the art for inhibiting or preventing the relative rotation between adjacently located fastener members, such as nuts or bolts; for example, such as may be positioned about a bolt circle on mating flanges or the like, these fail to provide the necessary structure which will prevent relative rotation between the fastener members.
U.S. Pat. No. 3,351,116 to Madsen, in one embodiment thereof discloses a pair of interengageable plate members having central apertures into which the polygonally-shaped heads of bolts are adapted to be inserted, and whereby the projecting edges or corners of the bolt heads will contact adjoining surface portions of the respective aperture in the plate members in which they are located such that during tightening and torquing of nuts which are in screw-fitted engagement with the bolt shanks, this preventing of rotation of the bolts will facilitate the tightening process by a worker.
U.S. Pat. No. 4,475,857 to Hiraiwa discloses a detent apparatus in which a plate has polygonally-sided recesses or cutouts formed at oppositely located edges thereof, each engageable by a close-fitting hexagonal member so as to inhibit relative rotation between the hexagonal members responsive to the application of rotational moments thereto.